Lifting jack for coal-cutting machines and the like



sept. 16, 1930. l, 6,099

mums JAcx van coAL curns ucn'rnss un fnl' Lm yv. c. BLACK med oct. 1,1921 z sheets-sheet' 1 Arwen/sy Sept. 16,1930. c. BLAcK l 1.776.099

LIFTING' JK FOR COAL CUTTING IGHINBS :um THE LIKE Fuga ont. 1, 1927 zsheets-sheet 2. 20 25 22 /NVENTC yfwm Patented Sept. 16, 1930 UNITED`s'rxras PATENT OFFICE WILLIAM CHRISTIE BLACK, orv DULLEY, ENGLAND,AssIeNoa To MATTHEW sMI'IH Y Moonnor BHUssELs,BHLGIUM f- LIFTING JACKnon @OAL-CUTTING MACHINES AND THE LIKEV Application filed rOctober 1,1927, Serial No.

The present invention relates to lifting jacks and it has particularreference to' screw jacks such as are used'coal cutting machines and thelike,`in which it is required to move 5. the machine bodily in order toobtain the necessaryA vertical and angular adjustment of 4the tools tosuitfvarying conditions of work.

p In machines of this kind it is customary to lo support the vframe orbody of the machine on lifting jacks located on either side of itslongitudinal" axis'," so that the frame may be raised or lowered whensuch jacks are oper'- ated together, or it'may be tilted to the de- 15sired angle by'opera'ting only the'jack or jacks on one side thereof. Inorder that the jacks may follow the tilt of the frame they areconveniently mounted on spherical feet. However if they are rigid withthe. machine frame, they have a tendency to'jam'when the machine istilted and it has been proposed to allow one of the feet to slidelaterally, causing allthe side stresses to bear on thefixed foot. Inanother case where both feet are 25. fixed, one jack only is heldrigidly in the machine whilst the other is free to accommodate itself tothe angle of tilt. ySuch arrangements, however, have certaininconveniences, and in particular that of weakening the support of themachine.

It is the object of my invention to obviate I these -inconveniences andto :provide lifting or adjusting jacks which will befreeof jamming andadapted to be rigidly held ina 35 machine frame without lrequiring anydisplacement of their supporting feet when the machine is tilted.

To this end the lifting jacks according to this invention are formed oftwo parts mountedeccentrically with respect to each other so as to'becapable of compensating by an angular motion a lateral displacementimparted to one of said parts. In the case of screw V jacks for coalcutting machines, the axis of the screw preferably extends parallel tothat of the spherical foot. l/Vhen one of the jacks is operated to tiltthe machine the screw automatically moves about the centre of such 50foot through the angle required to absorby 223,442,1and`in Belgiuml(Jcrsober 13, 1926i Vthe lateral movement corresponding to the' view ofa coalcutting machine equipped with screw jacks according tothisinvention. .f Fig. 3 shews a detail lin sectionon line A-B of Fig. 2. iY

Figsli is a cross section, on an scale, taken on line Cf-D of Figi 2.

Figs. 5 and -6 illustrate a screw 'jack onv a still larger scale, Fig.'being an `axial 'sec tion von line E--F of Fig. 6, and Fig. 6 across-section on line G-II of Fig. 5."

'In Fig. l, If'have'diagrammatically repreysented at l the frame ofacoal cuttingmachine of rectangular cross-section, supported by screwJacks resting on spherical `feet 2. In known structures wherein thejacks are rigidly. held in the machine frame the axes of the screwscoincide with the axes a of the sphericall feet vand if one only of thescrews is operated the `frame is tilted` to a positionsuch as shown indotted lines at 1, the axis of this screw taking .up theposition a,whereby the foot 2 supporting said Vscrew enlarged` v is caused to movelaterally to the position'2.

' In the structure according to my invention this lateral displacementis avoided owing to the fact that the screws are mounted eccentricallyto the spheres 2. Thus in Fig. 1 the vaxes of the screws are shown atand on the machines being tilted they will turn through any requiredangle up to 180o about the ce-ntres 0 of the spherical feet 2 and take'up thepositions b', the frame taking upthe position 1/ .while the feet2 remain stationary. VIn practice the axis a of each spher` ical footand vthe .axis b ofthe correspond-l ing screw are comprised in the samelongitudinalv plane (at right angles to the plane of Fig. l) so as toApermit of the axes b turning of the machine and on a pair of screw acks4 mounted in the machine trame 1 and symmetrically located on eitherside of the longitudinal axis.

The support 3 may be of any suitable construction capable of allowingfor universal movement of the trame within restricted limits. I haveshown in Figs. 2 and 3 a rather crude but convenient support of currentdesign consisting of a web 8 on the usual skid 5 supporting the entiremachine. Through an eye 6 in this web extends a bolt 7 secured to thebottom wall 8 of the frame 1 which is recessed at9 to accommodate the Yweb 3. The diameter of the eye 6 is substantially larger than thatof thebolt 7 and the recess 9k is proportioned so that the trame may have acertain freedom of oscillation about its longitudinal axis, in additionto' being able to swing about the pivot 7. 1 l

The screwjacks herein shown (Figs. 4to

E6) comprise each a screw 10 engaging'ran internaillylthreaded sleeve'11; Thecylindr'ical outer wall of this sleeve is concentric to the axisb of the screw 10 and has asnug y fit in a cylindrical rece-ssi'1v2inthe; machine Ywith the spherical foot frame l. Thesleeve 11ijs "securedby means of appin 13 to a member or projection 14 rigid 2 Vsupporting"-thfe screw jack. y i l As illustrated, the axis ofthe screw `andsleeve is eccentric to the spherical bearing and extendsv'parallel tothe axisa ojthe latter, theeccentricity being proportioned accordingk tothe magnitude of `the` lateral movement to be absorbed.` The `foot* 2'is mountedin'a bearing15, 16 which may be' secured in position on thesupportingplate 5,

To provide the desired rigid connection with the machine frame the screw'10 has an kannular top shoulder 19 `and onits upper fend 20 is screweda nut 21 lockedfby means of a pin 22. Between the shoulder 19 and nut 21is comprised a plate 23 rigidly secured to theframe 1 by bolts 24.Accordingly when `the screw 10 is rotated in one or4 the other directionby operating its polygonal head 25, it will lift the trame by means otthe shoulder 19 or lower it by means of the nut 21. Y t

' It onetonly of the screw jaclsis operated the screws 10 will follow`the tilt imparted tothe frame. Since the spherical feet 2 are Y'prevented fromv sliding laterally, the sleeves 11 will turn each aboutthe axis a of its toot,

t lthrough the angle required to compensate for l the lateral movementcorresponding toy the tilt of the frame This angle of course should notexceed 180o since locking then would take place, but the eccentricitycan be so proportioned that the lateral movement correspondingto anyamount of tilt required in practice may be compensated for by arotatable through an angle of.180 on anaxis 'parallel to the' axis ofsaid bore; l 1K3; In a lifting jack Afor `coal cutting matation of lessthan 180, a rotation of about 90o being fully sufficient in most cases.

It will be understood that the particular construction herein describedand illustrated may be varied without departing from the spirit of myinvention, y

l claim:

1. In a lifting jack for coal cutting machines andY thelike, thecombination of a member having a cylindrical bore 'therein,""acylindrical member engaging said bore and capable bothot sliding androtary motion therein, a supporting tootv Asecured to one end ot saidcylindricahmember,--saidtoot being rotatable through an angle of 180o onan axis "eccentric to said bore,andmeans 4for moving memberlhaving acylindrical boretherein, at

cylindrical sleeve, engaging said bore, l-said lsleeve being .internallyscrew-threaded,a

screw in threaded engagement with'jsaid sleeve,1 said screw being'rotatably mounted in said* member and'lockedv against: axial" movementwith respect-(thereto,4 and fasupporting 'toot .eccentrically' securedtotthelower end of said sleeve,I saidfootbeing rochines and the like',the combination `ofa ing screw rotatably mounted in said member andlocked against axial movement with` respect thereto, said screwbeingcoaxial with said sleeve and said bore, and aspherical supportingftootrotatable through an.y angle fof 180O on an axis'parallel to thevaxisofsaid screw, said toot being secured tothe' lower end ofsaid sleeve.

4. In va lifting jack for coal cutting machines and the like,thezcombinationzot asta-y `tionary bearing, a vspherical-" tootlrotatable thfrough 180o in said bearin-g a cylindrical member resting onsaidfoot, the axis of said cylindrical member being parallel-tothat-ofsaid foot and bearing, a casing having a cylindrical bore surroundingsaid cylindrical member, and means interposed between said casing andsai'drcylindrical member for moving said casing` axially of said member.

5. In a. coal cutting machine, the .combi-na` tion with a frame having apair of cylindrical bores, of internally threaded cylindrical sleevesslidable and rotatable ,eachl through an angleotl 180o in saidbores,`co-operating screws rotatable in saidrframe and'glocked againstaxial movementv relative thereto, spherical supporting teetrsecured oneto the lower end of each of said sleeves, said feet beingrotatableeachon an axis parallelto, A l

that of the sleeve secured thereto; 'y

Vmember having a cylindrical bore therein, an internally Lthreadedcylindrical'A 4sleeve slidable and rotatable in said bore,aco-operatrice6. In a Coal cutting machine, the combination With a frame having a pairof cylindrical bores, of a skid, a pair of spherical bearings fixed onsaid skid, a rotatable spherical foot in each of said bearings, acylindrical member mounted eccentrically on each of said feet, each ofsaid cylindrical members being slidably engaged and capable of rotationthrough 180O in one of said cylindrical bores,

and means interposed between said frame and each of said cylindricalmembers for lifting and lowering said frame With respect to either ofsaid members.

WILLIAM CHRISTIE BLACK.

